The present invention relates to a cuff for joining together pipes. Particularly, but not exclusively, it relates to a cuff for joining together two pipes in which the cuff is slideable along at least part of one of the pipes to allow nesting of the pipes.
It is understood that the term xe2x80x9cpipexe2x80x9d referred to throughout the specification includes a rigid pipe or a flexible pipe (hose).
Cuffs of the types referred to above are known for joining the flexible hose portion and the rigid pipe portion of a wand of a vacuum cleaner 1 as shown in FIG. 1. The cuff 10 is attached to one end of the flexible, extendable hose portion 14 of the wand 3. The cuff 10 is slideable along the rigid pipe portion 16 so that the rigid pipe portion 16 nests within the flexible hose portion 14 for storage but can be fully extended when in use. In the stored position, the cuff is slid to the uppermost end of the rigid pipe portion 16, the flexible hose portion 14 rests over the rigid pipe portion 16 and the assembly is then clipped onto the body 5 of the vacuum cleaner with the nozzle 7 of the wand 3 uppermost. The nozzle 7 then forms a handle for manoeuvring the vacuum cleaner over a surface to be cleaned. For above-floor cleaning the wand 3 is unclipped from the body 5 of the vacuum cleaner and the cuff 10 is slid to the lowermost end of the rigid pipe portion 16 so that the wand 3 is fully extended as shown in FIG. 1. The wand 3 can then be used to clean awkward areas. The flexible pipe portion 14 is extendable giving the user full flexibility.
This type of cuff provides a partial seal between the flexible hose portion and the rigid pipe portion so that the air flow path defined by the flexible hose, cuff and rigid pipe portion is continuous but not fully airtight. This can cause loss of suction. The cuff also ensures that the rigid pipe portion and the flexible hose portion are not detached from each other. However, the cuff does not hold the rigid pipe portion with respect to the flexible pipe portion and therefore the cuff can slide along the rigid hose portion during use. This causes the end of the rigid pipe portion to project into the flexible pipe portion which, since the flexible pipe portion will normally follow a curved path, in use, the rigid pipe portion contacts the inner wall of the flexible pipe portion causing wear at the point of contact. At the lowermost end of the rigid pipe portion, there is provided means for preventing it from completely falling out of the cuff. Therefore, for above-floor cleaning tools must be attached to the remote end of the rigid pipe portion. Since the rigid pipe portion is inflexible, it can be awkward for cleaning particularly confined spaces.
Another type of known cuff provides means for retaining two or more rigid pipe portions in predetermined positions with respect to each other. Examples are shown and described in WO 94/10494, U.S. Pat. No. 5,090,747 and U.S. Pat. No. 4,863,201. However, such cuffs are generally bulky and are therefore unsuitable for use in situations in which space and weight are at a premium as in the case, for example, of a vacuum cleaner wand of the type shown in FIG. 1, particularly a domestic vacuum cleaner.
The present invention seeks to provide a cuff for joining together two pipes which can retain the pipes at a predetermined position with respect to each other and which is also compact. The present invention also seeks to provide a cuff for joining together two pipes and which is suitable for use in a wand for a vacuum cleaner, particularly a domestic vacuum cleaner.
According to the present invention, there is provided a cuff for joining together an inner pipe and an outer pipe, the cuff being slideable along at least part of the inner pipe to allow nesting of the pipes, the cuff comprising a housing and an interlocking member supported by the housing, the interlocking member lying, in use, around the inner pipe in a plane extending transversely to the longitudinal axis of the inner and outer pipes, and having an actuator portion and an interengaging portion for interengaging with the inner pipe, the interengaging portion lying, in use, on the side of the inner pipe remote from the actuator portion so that, when the interlocking member is translated within the plane on actuation, the interengaging portion is released from the inner pipe, characterised in that a pair of diametrically opposed lugs are located on the interlocking member and in that a compression spring acts between each lug and the housing so as to bias the interengaging portion into engagement with the inner pipe.
The interlocking member of the cuff according to the present invention provides means for retaining the cuff at a predetermined position with respect to the inner pipe, thus preventing slippage of the inner pipe when in use and minimising wear. Further, the release of the interengaging portion from the inner pipe by translation of the interlocking member in the plane, which extends transversely to the longitudinal axis of the pipes, provides a more compact cuff which is more suitable for storage where space is minimal. Furthermore the interlocking member generally follows the shape of the pipes to minimise the size of the cuff. The outer edge of the interlocking member and the housing of the cuff are preferably circular or substantially circular so as to conform to the shape of the inner and outer pipes to further minimise the size of the cuff.
In providing two compression springs, the bias required to maintain engagement of the tongue and groove is shared. Therefore, the size of the springs can be further reduced and hence also the size of the cuff housing. The cuff enables the inner pipe to be completely released from the cuff so that tools can be inserted directly and held in place by the interlocking member.
Preferably, the interengaging portion interengages the inner pipe by a tongue and groove arrangement. In alternative arrangements, the interengaging portion comprises one or two tongues which interengage at least one groove in the inner pipe, or the interengaging portion comprises one or two grooves which interengage a corresponding tongue on the inner pipe.
Preferably, the actuator portion comprises a push-button which, when pressed, counteracts the bias of the compression springs to release the interengaging portion from its engagement with the inner pipe.
In a preferred embodiment, the interengaging portion comprises a substantially annular ring and the actuator portion is located on the annular ring diametrically opposite the interengaging portion and perpendicular to that joining the lugs.
In a preferred embodiment, the cuff further comprises a second interlocking member lying in a plane extending transversely to the longitudinal axis of the inner and outer pipes, and having a second actuator portion and a second interengaging portion for interengaging with the inner pipe, the second interengaging portion lies on the side of the inner pipe remote from the second actuator portion so that, the second interlocking member is translated within the plane on actuation in a direction opposite to the translation of the first interlocking member to release the second interengaging portion from the inner pipe.
Preferably, the cuff comprises a seal for sealing the housing and the interlocking member with the inner pipe. Therefore, an improved seal is achieved which provides improved suction when the cuff forms part of a vacuum cleaner.
The cuff of the present invention is particularly suitable for joining the inner and outer pipes of a wand for a vacuum cleaner where the inner pipe is a rigid pipe and the outer pipe is a flexible pipe.
In the case of use in a wand for a vacuum cleaner therefore, tools can be attached to the flexible hose for above-floor cleaning making the cleaner easier to use in particularly awkward places.